Merged PR 623: TAP003 Local Host index error causing index error.

## Summary

Adds an additional if statement to catch the edge case.

This bug came out of another bug-fix made in !612 in which the manipulation stage logic was altered (the last host was being skipped over).

## Test process
Ran the pre-existing tests (in milpac as well)

## Checklist
- [x] PR is linked to a **work item**
- [x] **acceptance criteria** of linked ticket are met
- [x] performed **self-review** of the code
- [ ] written **tests** for any new functionality added with this PR
- [ ] updated the **documentation** if this PR changes or adds functionality
- [ ] written/updated **design docs** if this PR implements new functionality
- [ ] updated the **change log**
- [x] ran **pre-commit** checks for code style
- [x] attended to any **TO-DOs** left in the code

Fixing an issue where if tap-003 were to attempt to change the password of it's starting node an index error would cause a crash. (only if the starting host was the last host in the `account_changes` config option)

Related work items: #3107

src/primaite/game/agent/scripted_agents/TAP003.py

@@ -355,7 +355,12 @@ class TAP003(AbstractTAP, discriminator="tap-003"):
                             "new_password": self._next_account_change["new_password"],
                         }
                         self.logger.info("Changing local password.")
-                        self._next_account_change = account_changes.pop(0)
+                        # Catch last host edge case.
+                        if len(account_changes) == 0:
+                            self.logger.info("No further account changes required.")
+                            self._next_account_change = None
+                        else:
+                            self._next_account_change = account_changes.pop(0)
                         self._change_password_target_host = self.current_host
                     else:
                         # make sure we are logged in via ssh to remote node
@@ -384,6 +389,7 @@ class TAP003(AbstractTAP, discriminator="tap-003"):
                                 ],
                             }
                             self.logger.info(f"Changing password on remote node {hostname}")
+                            # Catch last host edge case.
                             if len(account_changes) == 0:
                                 self.logger.info("No further account changes required.")
                                 self._next_account_change = None